Groups of galaxies (which can be defined as objects with total masses \(M_{500}\)  in the range \(10^{13}-10^{14} M_\odot \) , though see [1]} for the unavoidable ambiguity of the definition of a galaxy group) bridge the mass spectrum between L* galaxies and galaxy clusters. They are known to host a significant fraction of the number of galaxies in the Universe [2]}, [3]}, they form in the filaments of the cosmic web and not only in the nodes [4]}, and they are bright enough to be relatively easily observable in X-rays, while having low enough masses such that complex baryonic physics (e.g. cooling, galactic winds, AGN feedback) begins to dominate above gravity, making these objects more than simple scaled down versions of galaxy clusters [5]}, [6]}.
Groups of galaxies appear as critical systems to understand the process of structure formation, the dynamical assembly of baryons in the dark matter halos, and the complex physical processes affecting both the gas and the stellar components. For all the above reasons it is important to study metals in groups: if for example it is more controversial with respect to clusters that they can be considered as "closed box", they can provide key information on the processes resulting in the redistribution and loss of metals and it is clearly instructive to investigate the metal budget in different types of systems [7]}.
